1. Field of the Invention
The invention relates generally to circuit breakers and, more particularly, to a circuit breaker having a bumper.
2. Description of the Related Art
Circuit breakers are generally well known and are used in numerous applications. Circuit breakers can be used to interrupt a circuit under certain predetermined circumstances, and can be used for other purposes.
A typical circuit breaker might include a set of separable contacts that can be separated in certain predetermined circumstances to open a circuit. The separable contacts might include one or more movable contacts that are disposed on a movable arm which, when moved, can separate the movable contacts from one or more stationary contacts to interrupt the circuit. The movable arm may, for example, be a movable arm that is movable by an operating mechanism. While circuit breakers have been generally effective for their intended purposes, such circuit breakers have not, however, been without limitation.
Circuit breakers are oftentimes required to interrupt a circuit very rapidly. The operating mechanism may need to pivot the movable arm at a high speed in order to interrupt the circuit. In addition to including an operating mechanism, some circuit breakers may be configured to further include a “blow open” feature. Such a “blow open” feature may be provided, for instance, by arranging the conductors within the circuit breaker in such a fashion that the electrical fields around the conductors magnetically propel the movable arm to rapidly pivot in certain overcurrent conditions.
A movable arm that is moving at a high velocity must ultimately be stopped and the kinetic energy thereof dissipated in some fashion. Some circuit breakers include hard stops against which the movable arms impact, although such hard stops have drawbacks that should be apparent. While certain cushioning systems can be employed to decelerate a movable arm, many cushioning systems have only a limited ability to dissipate the energy of the movable arm, which can undesirably result in a rebounding of the movable arm and potential consequent reclosing of the circuit.
The mounting and retention of such cushioning systems within circuit breakers has also had limitations. While some cushioning systems have been adhered within circuit breakers, the adhesives employed have been known to become unreliable over time. Moreover, the use of such adhesives tends to introduce various uncertainties into the operation of the breaker based upon, for example, the quantity of adhesive employed, the techniques used in applying and curing the adhesive, and the like. Additionally, an adhered cushioning system can be difficult to replace. It thus would be desirable to provide an improved circuit breaker having an improved cushioning system.